Notations and units:

Re = Reynolds Number, Nu = Nusselt Number, Pr = Prandtl Number, Gr = Grashof Number, µ = Dynamic viscosity

= Kinematic viscosity,= Diameter or Length based on the environment, C = Specific heat, = Coefficient of friction, K = Thermal conductivity, h = Heat transfercoefficient, g = acceleration due to gravity, β = Coefficient of thermal expansion, T = Temperature

Units of the notations are in SI units.

**1.Stanton Number** = Heat transferred into fluid / Thermal capacity of the fluid

Stanton Number = =

**2.Schmidt Number** = Momentum diffusivity or kinematic viscosity / Mass diffusivity

**3.Sherwood Number** = Convective mass transfer / Diffusion mass transfer

**4.Lewis Number** = Thermal diffusivity / Mass diffusivity

**5.Peclet Number** = Convective heat transfer / Conductive heat transfer

**6.Reynolds Number** = Inertia force / Viscous force

Reynolds Number =

= dynamic viscosity / mass density

**7.Euler Number **= inertia force / pressure force

**8.Prandtl Number** = diffusion of momentum / diffusion of heat

Prandtl Number =

Prandtl Number = Velocity boundary layer thickness / Thermal boundary layer thickness

**9.Nusselt Number** = Conduction resistance of the fluid / Convection resistance of the fluid

Nusselt Number =

**10.Grashof Number** = (buoyancy force / viscous force) x Re

Grashof Number =

**11.Cauchy Number** = inertia force / elastic force

**12.Fourier Number** = ability of the solid to conduct energy / ability to store energy

**13.Rayleigh Number** = Gr x Pr

**14.Froude Number** = inertia force / gravity force

**15.Weber Number **= inertia force / surface tension force

**16.Mach Number** = velocity of the stream / velocity of the sound

**17.Biot Number** = internal conductive resistance of the solid / convective resistance of the fluid

Biot Number =